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Sunday night 29/6/08 23.30 - 01.30

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For your viewing pleasure, some more ramblings from North Norfolk that I posted on our society yahoo group and thought could go here as well.

29/6/08 23.30 - 01.30

Hi all.

I've been inspired to write a few notes after receiving several

emails over the past few days from Andrew R. and Dale who don't seem

to have slowed down their observing at all over the midsummer period,

despite the fact that there is currently no astronomical darkness

until late July. Anyway, just because the skies are still blue at

midnight doesn't mean there's nothing to see. As Martin's post shows,

there's the moon, NLC's, and Jupiter is making the best of a very

poor opposition at the moment. Hmm, that's about it really. Or so I

thought until I had a quick look outside on Sunday night after

watching a few hours of Glastonbury on TV, and realised that it was

clear and dark enough to see some strange shiny things in the sky. Ah

yes, I remember, stars.

Obviously, now that the nights are drawing in we need to start

thinking seriously about re-familiarising ourselves with the skies

that we may have forgotten over the past, errr…, month.

By 11.30, I had the TV102 set up in the garden, it didn't really need

any cool down time as it was warmer outside than indoors. This was

going to be a totally unplanned session, so I turned to what I always

rely on for a bit of inspiration – Sky and Telescope, or more

specifically Sue French and Ken Hewitt-White's articles in the June &

July issues.

Hercules was high overhead at this time, so I had a quick look at M13

& M92, just to get a rough idea of the background sky brightness, and

the likelihood of seeing anything fainter than 3rd magnitude. Both

were pleasingly obvious even at 25x, and grainy at 45x & 88x, but

rather smaller than I was expecting. Even though the 102 is a very

contrasty scope, it lacks the aperture needed to tease out the

fainter halo stars from both of these clusters, particularly at this

time of year.

So I didn't expect much from my next target – NGC6229, a mag. 9.4

globular in the far north of Hercules which is usually overlooked in

favour of the more obvious Messier pair. Surprisingly, it was easily

visible, forming the tip of a small triangle with two 8th magnitude

stars. It looked similar to a very small planetary nebula, I couldn't

see any significant halo, just a small faint spot at 88x. Moving

south to Rho Herculis, I was able split this 4.1" double at 88x,

although at 45x there was only a vague hint of a dark line between

the pair, which made it obvious that the seeing was as I had

suspected earlier – rubbish. Too much moisture in the air, and too

much heat. It was a good thing that most of the rest of the "Sue

French" list was asterisms and wider doubles. Further south still was

Delta Herculis at 12", which also proved difficult at 88x as the 3rd

mag. primary almost overpowered the 8th mag. secondary, not helped by

the sky conditions. 56 Herculis was also an uneven magnitude pair,

slightly easier at 18", and was split at 45x. I would like to be able

to say there was a noticeable colour contrast in all these doubles,

but to me they just looked creamy-white.

DoDz8 is a small asterism near Delta Her., and was rather

underwhelming. Two pairs of stars with a couple of fainter ones

either side of a line between them does not a cluster make, in my

book. Maybe Sue can see something I can't.

Mu Herculis was relatively easy at 45x, thanks to it's separation of

35", although it's another one where the primary is several

magnitudes brighter than the secondary.

There is a tiny 11th mag. planetary nebula in the area, Vy 1-2, but I

passed over this as a challenge for a darker night, and moved on to

Markov 1 which was by far the most aesthetically pleasing object of

the night. At 25 & 45x it bears a resemblance to the naked-

eye "teapot" asterism of Sagittarius, being composed of nine 9th and

10th mag. stars, with an easily split double (24" Dembowski 17) among


Slightly less impressive was DoDz9 to the north-east. Again, a few

scattered stars across about ½ degree, only slightly richer than the

general background makes me wonder what would be seen in darker skies

with more aperture.

My final "Sue" (as opposed to a Messier) was Webb's Wreath, which is

a small oval shaped asterism of faint to very faint stars, with a

single 7th magnitude star to one side. I found one side of the wreath

easier to pick out, and it reminded me of an extremely faint and

small version of Corona Borealis.

Ken Hewitt-White usually offers a selection of deep sky goodies for

small scopes each month, but he must have experienced midsummer

observing at northern latitudes, as his June column was a double star

tour of Bootes. Way to go Ken!

I remember doing most of these earlier in the year, but that was in

February, and there was frost on the scope. This time, keeping cool

was more of a problem, and even after only an hour outside everything

was damp because of the humidity level.

Starting off just south of Arcturus was the only non-double on the

list, an asterism called Picot 1. It looks exactly as he described

it, a short curvy line of 9th to 11th magnitude stars like a crawling

caterpillar. Very cool.

Slightly north of Arcturus is Struve1825, which was only elongated at

88x, and barely split at 146x, even though both components are rather

faint, as the separation is only 4.4". The seeing would obviously be

the limiting factor in what was "doable" for the rest of the tour.

Xi Bootis off to the east was slightly easier to split at 88x, as

it's almost 7", although I couldn't see the colour contrast that is

mentioned in S&T. Same story with Pi Bootis to it's southwest,

although the magnitude difference is less, making the 6" separation

seem smaller than it would appear under better skies. Struve 1835 is

a 6" double at the end of a short line of 3 stars, and was a clean

split at 88x, again no colour was seen.

Mag. 2.6 Epsilon Bootis (2.9") was impossible to separate, looking

like a elongated blob even at 146x, and the seeing was not really

good enough to "zoom" in any more with the 3-6mm Nagler. This is a

superb eyepiece for double star work, but using it to it's full

potential needs a driven equatorial mount and good seeing, neither of

which I had.

So I swapped it for a 19mm Panoptic (45x) and had a quick look at

Kappa and Iota Bootis in the far north of the constellation. This

reasonably close pair reminded me of the double-double in Lyra,

although neither pair is as difficult, and Iota is about 3 times

greater separation than Kappa.

I'd been out for nearly 2 hours, hardly a marathon session by any

standard, but it felt like an all-nighter as the skies to the north

were distinctly blue, just like the first hint of dawn at the end of

a march Messier Marathon.

I couldn't end the night without a look at Jupiter, boiling away in

the warm and humid air low in the south. At least I saw all four

galilean moons – was I seeing disks at 88x? No, just the effects of

5" seeing. Oh, and a couple of equatorial belts. That's it really. No

GRS, no white ovals, nothing. Time to call it a night I think.

Roll on winter………

Cheers everyone,

Dave Howes

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